CN111615256A - Non-exposed hole double-sided conducting circuit film and manufacturing method thereof - Google Patents

Abstract

The invention relates to a non-open-hole double-sided conduction circuit film and a manufacturing method thereof. The invention has the effects of preventing the slurry from overflowing during double-sided printing and ensuring that the surface of the induction electrode is complete and has no exposed hole.

Description

Non-exposed hole double-sided conducting circuit film and manufacturing method thereof

Technical Field

The invention relates to the technical field of circuit double-sided conduction, in particular to a non-open-hole double-sided conduction circuit film and a manufacturing method thereof.

Background

In the early Printed Circuit Board (PCB) and flexible printed circuit board (FPC) technologies, a copper-clad layer is first attached to the surface of a base material, and a Plated Through Hole (PTH) is formed by punching and then electroplating. The through hole shape of the plated through hole before electroplating is helpful for the double-sided distribution of the etching solution for etching the circuit in the wet process. However, with the development of tiny thinning of devices and the change of manufacturing processes, the circuit film has a thinner structure than a flexible circuit board, and the biggest difference between the two is that the circuit film does not use copper foil, an adhesive layer does not exist between a circuit and a base material, no etching process is used in manufacturing, the thickness of the whole product of the circuit film is more biased to a diaphragm rather than a plate, and the whole product of the circuit film has better bending and flexibility characteristics. However, in the process of manufacturing the circuit film, the circuit structure is directly printed by using metal paste such as silver paste, and the design of the through hole with two-sided conduction causes overflow pollution of the paste during printing, which easily causes the problem of inaccurate circuit pattern and short circuit of the circuit.

The invention patent application publication No. CN105802345A discloses a nano metal conductive ink, a preparation method thereof and a printed circuit board, wherein the specific nano metal conductive ink is adopted, ellipsoidal conductive nano metal particles in printed liquid drops generate stronger capillary interaction force among particles depending on the shapes of the particles, the ellipsoidal conductive nano metal particles are mutually dragged depending on the interaction force among the particles, a larger force field is integrally formed, and the ellipsoidal particles form a loose aggregation structure on the liquid surface due to the strong and remote inter-particle attraction force. The aim is to prevent the suspended particles from moving to the edge of the drop, to suppress the coffee ring effect and to create a uniform ink print quality. Such related prior art mainly utilizes the characteristics generated by the ellipsoidal nano metal particles in the conductive ink in single-sided printing to improve the capillary flow of the ink which continuously flows to the edge when the ink is evaporated. In the case of double-sided ink printing, spherical metal nanoparticles, whether elliptical or other shapes, may penetrate through the membrane to the other surface of the membrane.

The invention patent application publication No. CN104333983A discloses a hole filling printing process of a membrane switch, which comprises the following steps of preparation of a PET membrane circuit board, via hole drilling, positioning hole drilling, printing, drying and UV printing, wherein during via hole drilling, the precision of drilling is ensured by processing according to the hole position on a contrast film, and the deviation of two-side printing is ensured by drilling the positioning hole on the PET membrane circuit board and then performing positioning twice by using a sleeve positioning needle on a printing machine during printing. The electrical connection of the positive and negative sides of the PET film circuit board is realized by pouring silver paste into the via hole, and when the positive and negative sides are printed with the silver paste, the silver paste can be automatically poured into the via hole. In the related art, silver paste may form spread contamination on the other surface when the hole filling printing is performed on the first surface.

The invention patent application publication No. CN109767945A discloses a membrane switch and a processing method thereof, wherein a silk-screen printing process is adopted, circuits are respectively printed on the front and back surfaces of a circuit material to form a lower circuit board, and the lower circuit board is dried; arranging a positioning hole on the lower circuit board, and attaching and fixing the circuit component on the surface of the lower circuit board through the positioning hole; sticking a back adhesive on the back surface of the lower circuit board to form a back adhesive layer; and the front surface of the lower circuit board is adhered with the elastic sheet, and the elastic sheet is adhered and fixed on the lower circuit board through the elastic sheet covering film. The circuit board is the circuit film of two-sided printing promptly down, has positive circuit and reverse side circuit, and the offering of locating hole is after the circuit board forms down for circuit components and parts's attached fixed, the shell fragment subsides are established on the front of circuit board down, and the shell fragment direct mount is in the bottom that the elastic coating membrane was covered for the shell fragment is difficult for the off-position in transportation or use. Such related art relates to the assembly and positioning of the multilayer structure of the circuit film, and does not teach how to achieve the conduction between the front side circuit and the back side circuit.

Disclosure of Invention

The invention mainly aims to provide a non-open-hole double-sided conducting circuit film, which mainly aims to solve the problem of slurry overflow pollution during printing in the double-sided circuit film manufacturing process.

The invention mainly aims to provide a manufacturing method of a non-open-hole double-sided conduction circuit film, which is used for realizing the technical effect of double-sided printing and double-sided conduction of the circuit film without open holes.

The main purpose of the invention is realized by the following technical scheme:

a non-open-hole double-sided conduction circuit film is provided, which comprises:

the insulation film is provided with a front surface and an opposite back surface, and the insulation film is also provided with a first capillary blocking hole which penetrates through the front surface and the back surface;

the first conductive printing layer is formed on the back surface of the insulating film and comprises a first overflow-preventing pad which closes one end of the first capillary-preventing hole, and the first capillary-preventing hole is used for preventing printing slurry of the first conductive printing layer from overflowing to the front surface;

the second conductive printing layer is formed on the front surface of the insulating film and comprises a first sensing electrode and a main circuit structure, the first sensing electrode is electrically connected to the first overflowing preventing pad in a mode that the second conductive printing layer is filled into the first capillary blocking hole by slurry, and the first overflowing preventing pad is used for preventing printing slurry of the second conductive printing layer from overflowing to the back surface.

By adopting the technical scheme, the capillary blocking hole of the insulating film and the overflow-preventing pad for sealing the capillary blocking hole are utilized, the first capillary blocking hole can prevent the printing slurry of the first conductive printing layer from overflowing to the front side of the film, and the first overflow-preventing pad can prevent the printing slurry of the second conductive printing layer from overflowing to the back side of the film, so that the double-sided slurry printing and double-sided conduction of the circuit film are realized, and the first sensing electrode has a complete electrode surface without exposed holes.

The invention may in a preferred example be further configured to: the first sensing electrode and the first anti-overflow pad are electrically connected through a plurality of first capillary blocking holes in the first sensing electrode, the first sensing electrode is aligned to the first anti-overflow pad, and the coverage area of the first sensing electrode is larger than that of the first anti-overflow pad.

By adopting the preferable technical characteristics, the plurality of first capillary blocking holes are positioned in the first sensing electrode to electrically connect the first sensing electrode and the first anti-overflow pad, and when the first sensing electrode is aligned to the first anti-overflow pad and has a larger coverage area, the first anti-overflow pad is completely hidden on the back of the first sensing electrode, so that the sensing action or the electrode function of the first sensing electrode is not influenced.

The invention may in a preferred example be further configured to: the second conductive printing layer comprises a short circuit directly connected with the first sensing electrode, the first sensing electrode is electrically connected with the first anti-overflow connecting pad through the short circuit and the first capillary anti-plugging hole, and the first sensing electrode is not aligned with the first anti-overflow connecting pad.

By adopting the preferable technical characteristics, the short circuit of the second conductive printing layer is used as an extension circuit which is directly connected with the first sensing electrode on the front surface of the film, so that the wiring length of the back surface of the film is shortened, and in addition, a wiring structure which penetrates through the first sensing electrode does not exist on the back surface of the film, so that signal interference is avoided.

The invention may in a preferred example be further configured to: the second conductive printing layer further comprises a second sensing electrode, and the main circuit structure comprises a first connecting circuit which is not directly connected with the first sensing electrode and a second connecting circuit which is directly connected with the second sensing electrode; the insulating film is also provided with a second capillary blocking hole which penetrates through the front surface and the back surface; the first conductive printing layer also comprises a second overflow-resistant pad and a routing of the secondary circuit structure, the second anti-overflow pad seals one end of the second capillary anti-overflow hole, and the routing crosses over a part of the second sensing electrode and is connected with the first anti-overflow pad and the second anti-overflow pad; the first connecting circuit is also electrically connected to the second anti-overflow connecting pad in a mode of filling the second capillary anti-plugging hole with slurry; preferably, the first and second electrodes are formed of a metal, the wires are connected in series with all the first resistance overflow connecting pads, and the first sensing electrodes are equipotential reference electrodes.

By adopting the preferable technical characteristics, the second capillary blocking hole of the insulating film is utilized, the back wiring is used for connecting the first capillary blocking hole and the second capillary blocking hole, and the second capillary blocking hole crosses the second sensing electrode on the front surface of the film, so that the connecting circuits of the first sensing electrode and the second sensing electrode are not mutually connected in series. Preferably, all the first resistance overflow pads are connected in series by the traces on the back surface of the film, the first sensing electrodes are equipotential reference electrodes, in different examples, all or part of the traces can be used to complete the series connection of all the first resistance overflow pads, specifically, all of the traces are formed as relatively complete serial lines, and part of the traces are segmented lines separated into multiple segments, which need to form a serial line with the lines on other surfaces. Therefore, the main wiring of the circuit film can be located on the front surface of the insulating film.

The invention may in a preferred example be further configured to: the testing device comprises a front surface and a back surface, wherein the front surface is provided with a plurality of first connecting lines, the back surface is provided with a plurality of second connecting lines, the front surface is provided with a plurality of test areas, the first connecting ends electrically connected with the first connecting lines and the second connecting ends electrically connected with the second connecting lines are arranged in a same surface wire arranging interface area of the front surface or the back surface, preferably, the test areas electrically connected in parallel by the second connecting lines are arranged in a same surface test area of the front surface or the back surface, more preferably, the wire arranging interface area is positioned in the front surface, the test areas are positioned in the back surface, and more preferably, the lines connected.

By adopting the preferable technical characteristics, two connection end points which are respectively connected by two connecting circuits connected by two sensing electrodes are arranged in the same surface flat cable interface area of the insulating film, so that the same area and the same surface of the connection end points are converged, and the external connection is facilitated. Preferably, two kinds of test terminals respectively connected by two kinds of sensing electrodes are arranged on the same surface test area of the insulating film for testing the thin film circuit. More preferably, the flat cable interface area and the testing area are respectively positioned in the front surface and the back surface of the insulating film, so that the separation of external connection and circuit testing is not interfered. More preferably, the pitch of the test terminals is larger than that of the connection terminals by using the connection fan-out lines of the test terminals, so that the probes of the tester can be pressed and touched.

The invention may in a preferred example be further configured to: the insulating film is provided with a slotted shape at two sides of the flat cable interface area, so that the flat cable interface area on the surface is in a long strip shape.

By adopting the preferable technical characteristics, the insulation film is formed with a strip-shaped flexible integrated flat cable design by utilizing the slotted shapes at the two sides of the flat cable interface area, so that a welding point for connecting the flat cable and the flat cable is omitted.

The invention may in a preferred example be further configured to: the first induction electrodes are in a circular pad shape, the second induction electrodes are in a bad pad shape, and the second induction electrodes surround the first induction electrodes by taking circle centers of the first induction electrodes corresponding to the second induction electrodes as ring center points.

By adopting the preferable technical characteristics, the first induction electrode of the circular pad and the second induction electrode of the bad-shaped pad are utilized, and the second induction electrode surrounds the first induction electrode to form an induction interface in a gesture, electromotive force or short-distance non-touch mode, so that the circular pad can be used as a next-generation non-touch power-saving passive induction panel.

The invention may in a preferred example be further configured to: the first induction electrodes and the second induction electrodes are arranged in pairs, fixed gaps are formed between the first induction electrodes and the corresponding second induction electrodes, the first induction electrodes and the second induction electrodes which are arranged in pairs are arranged in the insulating film in a staggered matrix mode, preferably, the insulating film forms openings between paired matrix adjacent points and paired staggered points in the first induction electrodes and the second induction electrodes which are arranged in pairs, and preferably, the front surface coating film is provided with induction coil openings for exposing the first induction electrodes and the second induction electrodes which are arranged in groups.

By adopting the preferable technical characteristics, the specific configuration relationship and arrangement relationship between the first sensing electrode and the second sensing electrode are utilized to maintain the same sensing effect between the two sensing electrodes and have better sensing distribution in the sensing area. Preferably, openings are formed between adjacent points of the paired matrix and the paired dislocation points, and a gas permeable region can be formed in the sensing region to reduce adverse effects of gas flow on short-distance sensing. Preferably, the induction coil opening of the front surface coating film is utilized, so that the induction efficiency of the first induction electrodes and the second induction electrodes which are arranged in a group is not influenced.

The invention may in a preferred example be further configured to: the non-open-hole double-sided conduction circuit film further comprises a back covering film formed on the back face and a front covering film formed on the front face, the back covering film covers the first anti-overflow connecting pad, the front covering film covers the main circuit structure of the second conductive printing layer and exposes the first sensing electrode through an opening, the exposed face of the first sensing electrode is complete and nonporous, preferably, the printing thickness of the first conductive printing layer is larger than that of the second conductive printing layer, and preferably, the first capillary blocking hole is of a one-way blocking structure.

By adopting the preferable technical characteristics, the back surface coating film and the front surface coating film are utilized to protect the conducting circuits printed on two sides by the slurry and the anti-overflow connecting pads. Preferably, the printing thickness of the first conductive printing layer is larger than that of the second conductive printing layer, and the printing paste for forming the first conductive printing layer can have higher viscosity during paste printing so as to avoid seepage through the capillary blocking hole. Or preferably, the capillary blocking hole of the one-way blocking structure is used, so that the printing paste forming the first conductive printing layer is prevented from seeping out of the capillary blocking hole.

The main purpose of the invention is realized by the following technical scheme:

a manufacturing method of a non-open-hole double-sided conducting circuit film is provided, which is used for manufacturing the non-open-hole double-sided conducting circuit film of any one of the above technical schemes, and the manufacturing method comprises the following steps:

providing the insulating film, wherein the insulating film is provided with the first capillary blocking hole in advance;

back printing to form the first conductive printed layer;

printing on the front surface to form the second conductive printing layer;

wherein the first sensing electrode of the second conductive printed layer has an intact non-porous exposed shape;

preferably, a viscosity of a paste used for printing to form the first conductive printing layer is greater than a viscosity of a paste used for printing to form the second conductive printing layer.

By adopting the technical scheme, the printing slurry of the first conductive printing layer is prevented from overflowing to the front side of the insulating film by the first capillary resistance plug hole during the slurry back side printing, the printing slurry of the second conductive printing layer is prevented from overflowing to the back side of the insulating film by the first resistance overflow connecting pad during the slurry front side printing, the double-sided slurry line printing of the insulating film is completed, the first capillary resistance plug hole is naturally filled by the slurry of the front side printing, the double-sided conduction is achieved, the through hole plating process is not needed, and the first induction electrode on the front side of the film has a complete non-porous exposed shape so as to maintain consistent induction performance. Preferably, the through surface diffusion of the paste printed for the first time and the filling performance of the paste printed for the second time are controlled by using the viscosity difference of the double-sided printing, so that the double-sided conduction of the circuit film is completed.

In summary, the present invention includes at least one of the following technical effects that contribute to the prior art:

1. when the circuit film is used for double-sided printing of the conductive paste, the reverse diffusion pollution caused by the paste through the film through holes can be avoided;

2. the circuit connected with the induction electrode can be formed by printing the front side and the back side of the insulating film in a segmented mode;

3. the technology of plating through holes is replaced, the etching procedure is omitted, the double-sided electric connection which is printing and conducting is realized, and the connection of an elastic sheet or other longitudinal conducting components is not needed;

4. the induction electrode has a complete shape without exposed holes, has controllable induction efficiency, and is particularly suitable for a circuit board of a suspension type gesture induction interface control panel.

Drawings

FIG. 1 is a schematic diagram illustrating a front surface and a sensing electrode of a double-sided conducting circuit film without an exposed hole according to a first embodiment of the invention;

FIG. 2 is a schematic view showing a partial enlarged view of the back surface and the anti-overflow pad of the non-open-hole double-sided conductive circuit film according to the first embodiment of the invention;

FIG. 3 is a schematic view of the non-exposed double-sided conducting circuit film according to the first embodiment of the present invention, partially enlarged at the position of cutting the first sensing electrode and the first capillary stop hole;

FIG. 4 is a schematic view of the non-exposed double-sided conductive circuit film of the first embodiment of the present invention being partially enlarged at a position cut along the back trace and corresponding to the second capillary stop hole;

FIG. 5 is a schematic diagram illustrating a partial enlargement of the front surface and the sensing electrode of the non-open-hole double-sided conducting circuit film according to the second embodiment of the invention;

FIG. 6 is a schematic view showing a back surface and an anti-overflow pad of a non-open-hole double-sided conducting circuit film according to a second embodiment of the invention;

FIG. 7 is a schematic view of a non-exposed double-sided conductive circuit film cut along a back trace and partially enlarged at a capillary stop hole according to a second embodiment of the invention;

FIG. 8 is a schematic diagram showing a front side of a circuit connecting a first sensing electrode in a non-exposed double-sided conducting circuit film according to a second embodiment of the invention;

FIG. 9 is a schematic partial enlarged view of a non-exposed double-sided conducting circuit film at a cut capillary stop hole according to a third embodiment of the invention;

fig. 10 is a block diagram illustrating a manufacturing method of a non-open-hole double-sided conductive circuit film according to a fourth embodiment of the invention.

The number of the reference marks is 10, an insulating film, 11, a first capillary blocking hole, 12, a second capillary blocking hole, 13, a groove, 14, a hole, 20, a first conductive printing layer, 21, a first overflow blocking pad, 22, a second overflow blocking pad, 23, a routing wire, 30, a second conductive printing layer, 31, a first sensing electrode, 32, a second sensing electrode, 33, a first connecting circuit, 34, a second connecting circuit, 35, a short circuit, 41, a first connecting end point, 42, a second connecting end point, 50, a testing end point, 60, a back film, 70, a front film, 71 and an opening of an induction coil.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of embodiments for understanding the inventive concept of the present invention, and do not represent all embodiments, nor do they explain only embodiments. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention under the understanding of the inventive concept of the present invention are within the protection scope of the present invention.

It should be noted that if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture, and if the specific posture is changed, the directional indications are changed accordingly. In order to facilitate understanding of the technical solution of the present invention, the non-exposed double-sided conductive circuit film and the manufacturing method thereof of the present invention will be described and explained in further detail below, but the present invention is not limited to the protection scope of the present invention.

The accompanying drawings illustrate, to the extent possible, certain features of various embodiments that are common, and the differences or distinctions between embodiments are described in text or presented in contrast to the drawings, e.g., in order not to limit the location of capillary stop holes, a first embodiment shows in FIG. 3 that the capillary stop holes are aligned in the first sensing electrode, and a second embodiment shows in FIG. 7 that the capillary stop holes are outside the first sensing electrode. In order not to limit the number relationship between the capillary blocking holes and the first sensing electrodes (or the connection lines thereof), the first embodiment shows that the first sensing electrodes are correspondingly connected with 5 or other multiple numbers of capillary blocking holes in fig. 1, and the second embodiment shows that one front surface line connected with the first sensing electrodes is correspondingly connected with 1 capillary blocking hole in fig. 5. So as not to limit the shape of the capillary-blocking hole, fig. 3 in the first embodiment shows that the capillary-blocking hole has a flat-cut hole shape, and fig. 9 in the third embodiment shows that the capillary-blocking hole has a die-cut protruding hole shape. Therefore, based on the industrial characteristics and technical essence, those skilled in the art should correctly and reasonably understand and judge whether the individual technical features or any combination of a plurality of the technical features described below can be characterized in the same embodiment or whether a plurality of technical features mutually exclusive can be respectively characterized in different variant embodiments.

In order to facilitate understanding of the technical solutions of the present application, some terms appearing in the embodiments are explained. "capillary clogging" is a site that cannot be filled by capillary action under a particular situation or condition. The "printing paste" is a metal paste capable of forming a circuit by printing, and generally contains a high proportion of conductive particles and a binder, which are baked sufficiently to achieve electrical connection, and is usually a silver paste, and can also be a conductive paste mixed with other conductive particles. The "sensing electrode" is an electrode point that can be sensed by a gesture, electromotive force, or other means, and is usually a non-contact type, but may be a contact type.

Fig. 1 is a partially enlarged view of the front surface and the sensing electrodes of the two-sided non-open-hole through circuit film according to the first embodiment, fig. 2 is a partially enlarged view of the back surface and the anti-overflow pads of the circuit film, fig. 3 is a partially enlarged view of the circuit film cutting the first sensing electrodes 31 and the first capillary resistance holes 11, and fig. 4 is a partially enlarged view of the circuit film cutting the back surface trace 23 and the second capillary resistance holes 12. Referring to fig. 1 to 3, a non-exposed-hole double-sided conductive circuit film according to a first embodiment of the present invention includes:

a non-open-hole double-sided conduction circuit film is provided, which comprises:

an insulation film 10 having a front surface and an opposite back surface, the insulation film 10 further having a first capillary blocking hole 11 penetrating the front surface and the back surface (as shown in fig. 3), the insulation film 10 being usually made of PET, and the color being usually transparent, and also being white or black, the thickness of the insulation film 10 being usually 0.038-0.05 mm or less, the aperture of the first capillary blocking hole 11 being usually 0.1-0.15 mm;

the first conductive printing layer 20 is formed on the back surface of the insulating film 10, the first conductive printing layer 20 comprises a first overflow-preventing pad 21, one end of the first capillary-preventing hole 11 is closed, the first capillary-preventing hole 11 is used for preventing printing slurry of the first conductive printing layer 20 from overflowing to the front surface, and the thickness of the first conductive printing layer 20 can be 10-15 μm;

the second conductive printing layer 30 is formed on the front surface of the insulating film 10, the second conductive printing layer 30 includes a first sensing electrode 31 and a main circuit structure, the second conductive printing layer 30 electrically connects the first sensing electrode 31 to the first anti-overflow pad 21 in a manner that the first capillary anti-blocking hole 11 is filled with a paste, the first anti-overflow pad 21 is used for preventing the printing paste of the second conductive printing layer 30 from overflowing to the back surface, the thickness of the second conductive printing layer 30 may be 6-8 μm, and the printing paste of the first conductive printing layer 20 and the second conductive printing layer 30 may be a silver paste.

The implementation principle of the embodiment is as follows: by using the capillary blocking hole of the insulating film 10 and the overflow blocking pad for closing the capillary blocking hole, the first capillary blocking hole 11 can block the printing slurry of the first conductive printing layer 20 from overflowing to the front side of the film, and the first overflow blocking pad 21 can block the printing slurry of the second conductive printing layer 30 from overflowing to the back side of the film, so that the double-sided slurry printing and double-sided conduction of the circuit film are realized, and the first sensing electrode 31 has a complete electrode surface without exposed holes.

For the specific description of the first capillary blocking hole 11, in a preferred example, the first sensing electrode 31 and the first overflow blocking pad 21 are electrically connected through a plurality of first capillary blocking holes 11 located in the first sensing electrode 31, the first sensing electrode 31 is aligned with the first overflow blocking pad 21, and the coverage area of the first sensing electrode 31 is larger than that of the first overflow blocking pad 21. Therefore, the plurality of first capillary blocking holes 11 are located in the first sensing electrode 31 to electrically connect the first sensing electrode 31 and the first anti-overflow pad 21, and when the first sensing electrode 31 is aligned with the first anti-overflow pad 21 and has a larger coverage area, the first anti-overflow pad 21 is completely hidden on the back of the first sensing electrode 31, so that the sensing effect or the electrode function of the first sensing electrode 31 is not affected. Specifically, within the range of each sensing electrode 31, the plurality of first capillary blocking holes 11 are arranged in quincuncial piles, and are divided into a central blocking hole and a peripheral blocking hole surrounding the central blocking hole, and the electric connection of the central blocking hole is not affected by the breakage of the peripheral blocking hole.

Referring to fig. 2 and 4, in a preferred example of the specific description of the first conductive printed layer 20, the trace 23 is connected in series with all the first anti-overflow pads 21, and the first sensing electrode 31 is an equipotential reference electrode. In different examples, the first embodiment uses all the traces 23 to complete the series connection of all the first anti-overflow pads 21, specifically, all the traces 23 can form a relatively complete series circuit, and the first sensing electrodes 31 are equipotential reference electrodes. Therefore, the main circuit lines of the circuit film on the front surface of the insulating film 10 can have a larger elastic design margin for routing the lines individually connected to the second sensing electrodes (or electrodes requiring individual connection). When the first connection terminal 41 electrically connected to the first sensing electrode 31 is a ground connection or a low level connection, a potential difference is generated between the first sensing electrode 31 and the second sensing electrode 32, and a current change can be detected by the second connection terminal 42 electrically connected to the second sensing electrode 32. When the first connection terminal 41 electrically connected to the first sensing electrode 31 is connected at a high level, and is used as an input terminal, when the first sensing electrode 31 is connected in contact with the second sensing electrode 32, a current can be detected by the second connection terminal 42 electrically connected to the second sensing electrode 32, or a current change at the second connection terminal 42 can be detected by an external gesture or potential change using an electromagnetic effect.

As to the detailed description of the second conductive printing layer 30, in a preferred example, referring to fig. 1 and 3, the second conductive printed layer 30 further includes a second sensing electrode 32, and the main wiring structure includes a first connection wiring 33 not directly connected to the first sensing electrode 31 and a second connection wiring 34 directly connected to the second sensing electrode 32; with reference to figure 4 of the drawings, the insulating film 10 further has a second capillary blocking hole 12 penetrating the front surface and the back surface; the first conductive printing layer 20 further includes a second anti-overflow pad 22 and a trace 23 of a sub-circuit structure, the second anti-overflow pad 22 seals one end of the second capillary-resistant hole 12, and the trace 23 crosses over a portion of the second sensing electrode 32 and connects the first anti-overflow pad 21 and the second anti-overflow pad 22; the first connecting line 33 is also electrically connected to the second anti-overflow pad 22 by filling the second capillary-blocking hole 12 with paste. Therefore, the second capillary stop hole 12 of the insulation film 10 is used to connect the first capillary stop hole 11 and the second capillary stop hole 12 with the back trace 23, and cross over the second sensing electrode 32 on the front surface of the film, so that the connection lines of the first sensing electrode 31 and the second sensing electrode 32 are not connected in series.

Regarding one possible thickness relationship of the first conductive printed layer 20 and the second conductive printed layer 30, in a preferred example, the printing thickness of the first conductive printed layer 20 is greater than the printing thickness of the second conductive printed layer 30. Therefore, with the printing thickness of the first conductive printing layer 20 being greater than that of the second conductive printing layer 30, the printing paste forming the first conductive printing layer 20 can have a relatively high viscosity during paste printing to prevent seepage through the capillary-blocked pores.

In a preferred example of the external connection mode of the circuit film, referring to fig. 1, the first connection terminals 41 electrically connected to the first connection lines 33 and the second connection terminals 42 electrically connected to the second connection lines 34 are arranged on the same surface wiring interface region of the front surface or the back surface. Therefore, two connection terminals respectively connected by two connection lines connected by two sensing electrodes are arranged in the same surface wiring interface region of the insulating film 10, so that the same region and the same surface of the connection terminals are converged to facilitate external connection.

With regard to the specific description of the test connection of the circuit film, in a preferred example, referring to fig. 2, the test terminals 50 electrically connected in parallel by the second connection lines 34 are arranged in the same surface test area on the front surface or the back surface, in a more specific preferred example, referring to fig. 1 and 2, the flat cable interface area is located in the front surface, the test area is located in the back surface, and in a more specific preferred example, the lines connected to the surface test area extend in a fan-out direction toward the test terminals 50. Therefore, two kinds of test terminals 50 connected to two kinds of sensing electrodes respectively are arranged on the same surface test area of the insulating film 10 for testing the thin film circuit. The flat cable interface area and the test area are respectively positioned in the front and the back of the insulating film 10, so that the separation of external connection and circuit test is not interfered. With the fan-out lines connecting the test terminals 50, the pitch of the test terminals 50 will be larger than the pitch of the connection terminals, so as to facilitate the probe pressing of the tester.

Referring to fig. 1 and 2, in a preferred example, the insulation film 10 has a shape of a slot 13 on both sides of the bus bar interface area, so that the surface bus bar interface area is a long strip. Therefore, by utilizing the shape of the slots 13 on both sides of the flat cable interface area, the insulating film 10 itself forms a strip-shaped flexible integrated flat cable design to omit a section of welding point for connecting the flat cable and the flat cable.

As to the specific shape of the first sensing electrode 31 and the second sensing electrode 32, in a preferred example, the first sensing electrode 31 has a circular pad shape, the second sensing electrode 32 has a bad pad shape, and the second sensing electrode 32 surrounds the first sensing electrode 31 with the center of the circle of the first sensing electrode 31 as a circle center point. Therefore, the first sensing electrode 31 of the circular pad and the second sensing electrode 32 of the bad-shaped pad are utilized, and the second sensing electrode 32 surrounds the first sensing electrode 31 to form a sensing interface in a gesture, electromotive force or short-distance non-touch mode, so that the touch panel can be used as a next generation non-touch power-saving passive sensing panel. The width of the second sensing electrode 32 is specifically 10% to 50% of the diameter of the first sensing electrode 31.

In a preferred example of the combination relationship between the first sensing electrode 31 and the second sensing electrode 32, the first sensing electrode 31 and the second sensing electrode 32 are arranged in pairs, a fixed gap is formed between the first sensing electrode 31 and the corresponding second sensing electrode 32, and the first sensing electrode 31 and the second sensing electrode 32 arranged in pairs are arranged in the insulating film 10 in a staggered matrix manner. Therefore, the specific arrangement and arrangement of the first sensing electrodes 31 and the second sensing electrodes 32 are utilized to maintain the same sensing effect between the two sensing electrodes and to have a better sensing distribution in the sensing region. The fixed gap is smaller than the diameter or length of the first sensing electrode 31 and larger than the width of the second sensing electrode 32.

As for the specific shape explanation of the insulating film 10 outside the pair arrangement of the sensing electrodes, in a preferred example, the insulating film 10 forms the opening 14 between the pair matrix adjacent point and the pair dislocation point in the pair arrangement of the first sensing electrode 31 and the second sensing electrode 32. Thus, the formation of openings 14 between adjacent dots of the paired matrix and the paired sites of misalignment can form a gas permeable region within the sensing region of the device cell to reduce the adverse effects of gas flow on short-range sensing. In this embodiment, the insulating film 10 is provided with two openings 14, the opening 14 far away from the flat cable interface area is smaller and can be a rectangular hole or a square hole, 3 paired induction electrode coils are arranged on the periphery, the opening 14 in the middle of the film is larger and can be an irregular hole, 6 paired induction electrode coils are arranged on the periphery, and the circuit film can specifically have 8 induction electrode coils and can specifically correspond to an induction switch of one palm.

In a preferred example of the surface protection of the circuit film, referring to fig. 3, the non-exposed double-sided conductive circuit film further includes a back film 60 formed on the back surface and a front film 70 formed on the front surface, the back film 60 covers the first anti-overflow pad 21, the front film 70 covers the main circuit structure of the second conductive printing layer 30 and exposes the first sensing electrode 31 through an opening, and an exposed surface of the first sensing electrode 31 is completely non-porous. The back coating film 60 and the front coating film 70 are used for protecting the conductive circuits printed on two sides by the paste and the anti-overflow connecting pads.

In a more specific example, the front cover film 70 has an inductor opening 71 for exposing the first and second sensing electrodes 31 and 32 arranged in a group. By using the inductor opening 71 of the front surface coating 70, the induction efficiency of the first induction electrode 31 and the second induction electrode 32 arranged in a group is not affected. The "grouped configuration" is to combine one or more adjacent first sensing electrodes 31 and one or more adjacent second sensing electrodes 32 in a sensing coil region, and the "paired configuration" is to combine one adjacent first sensing electrode 31 and one adjacent second sensing electrode 32 in a sensing coil region. The insulation film 10, the back cover film 60 and the front cover film 70 may have an inductive isolation effect, or/and an inductive isolation effect on the film circuit may be obtained by using a shielding cover which is additionally assembled.

The second embodiment is different from the first embodiment in that the alignment relationship between the sensing electrode and the anti-overflow pad is not limited. FIG. 5 is a schematic diagram showing a front surface and a sensing electrode of a double-sided conducting circuit film without an exposed hole according to a second embodiment; FIG. 6 is an enlarged view of the backside of the circuit film and the anti-overflow pad; FIG. 7 is a partially enlarged view of the circuit film taken along the back trace 23 and at the capillary stop hole; fig. 8 is a schematic diagram showing a front side of a circuit connecting the first sensing electrode 31 in the conductive circuit film.

Referring to fig. 5 to 7, a non-exposed-hole double-sided conductive circuit film according to a second embodiment of the present invention includes:

a non-open-hole double-sided conduction circuit film is provided, which comprises:

an insulating film 10 having a front surface and an opposite back surface, the insulating film 10 further having a first capillary stop hole 11 penetrating the front surface and the back surface;

a first conductive printing layer 20 formed on the back surface of the insulating film 10, wherein the first conductive printing layer 20 includes a first overflow-preventing pad 21 that closes one end of the first capillary-preventing hole 11, and the first capillary-preventing hole 11 is used for preventing printing paste of the first conductive printing layer 20 from overflowing to the front surface;

the second conductive printing layer 30 is formed on the front surface of the insulating film 10, the second conductive printing layer 30 includes a first sensing electrode 31 and a main circuit structure, the second conductive printing layer 30 electrically connects the first sensing electrode 31 to the first anti-overflow pad 21 in a manner that the first capillary anti-plugging hole 11 is filled with slurry, and the first anti-overflow pad 21 is used for preventing printing slurry of the second conductive printing layer 30 from overflowing to the back surface.

In a preferred example, the second conductive printed layer 30 includes a short line 35 directly connected to the first sensing electrode 31, the first sensing electrode 31 is electrically connected to the first anti-overflow pad 21 through the short line 35 and one of the first capillary blocking holes 11, and the first sensing electrode 31 is not aligned with the first anti-overflow pad 21. Therefore, the short circuit 35 of the second conductive printing layer 30 is used as an extension circuit directly connected to the first sensing electrode 31 on the front surface of the film for shortening the length of the trace 23 on the back surface of the film, and the structure of the trace 23 passing through the first sensing electrode 31 does not exist on the back surface of the film, so as to avoid signal interference.

In a preferred example, the trace 23 is connected in series with all the first anti-overflow pads 21, and the first sensing electrode 31 is an equipotential reference electrode. In different examples, referring to fig. 7 and 8, the second embodiment is to connect all the first anti-overflow pads 21 in series by using the traces 23 on the back surface of the film, and the first sensing electrodes 31 are equipotential reference electrodes, and in the second embodiment, the portions of the traces 23 and the segmented lines on the front surface of the film are used together to complete the connection of all the first anti-overflow pads 21 in series, and the portions of the traces 23 are segmented lines separated into multiple segments, and form a serial line with the lines on the front surface of the film. Therefore, the main wiring of the circuit film can be located on the front surface of the insulating film 10.

The present invention also provides a third embodiment, which is different from the first second embodiment in the point of explaining that the shape of the capillary-blocking hole is not limited. In a third embodiment, FIG. 9 is a schematic diagram showing a circuit film at a section of a capillary blocking hole.

Referring to fig. 9, in a preferred example, the first capillary-clogging hole 11 has a one-way clogging structure. Therefore, with the capillary blocking hole of the one-way blocking structure, the printing paste forming the first conductive print layer 20 can be prevented from seeping out of the capillary blocking hole. The capillary blocking hole having the unidirectional blocking structure may be formed by punching or laser processing on the insulating film 10 in a direction toward the front surface of the film. The unidirectional blocking structure ensures that the paste printed on the back surface of the film is not easy to form the flow of capillary filling, and the paste printed on the front surface of the film is easier to form the flow of capillary filling. For example, capillary-blocking pores have a larger pore size at the front of the membrane and a protruding sharp-angled pore edge at the back of the membrane.

In addition, a fourth embodiment of the present invention further provides a method for manufacturing a non-exposed double-sided conductive circuit film, which is used for manufacturing the circuit film according to any of the above technical schemes. FIG. 10 is a flow chart of the manufacturing method. Referring to fig. 3 in conjunction with fig. 10, the method includes the following main steps:

step S1, providing the insulation film 10, wherein the insulation film 10 is provided with the first capillary blocking hole 11 in advance;

step S2 of back printing to form the first conductive printed layer 20, and,

step S3 of front printing to form the second conductive printing layer 30;

wherein the first sensing electrode 31 of the second conductive printed layer 30 has an exposed shape with no holes intact.

The implementation principle of the embodiment is as follows: when the paste is printed on the back side, the first capillary blocking hole 11 is used for blocking the printing paste of the first conductive printing layer 20 from overflowing to the front side of the insulating film 10, when the paste is printed on the front side, the first overflow blocking pad 21 is used for blocking the printing paste of the second conductive printing layer 30 from overflowing to the back side of the insulating film 10, so that double-sided paste circuit printing of the insulating film 10 is completed, the first capillary blocking hole 11 is naturally filled with the paste printed on the front side, double-sided conduction is achieved, a through hole plating process is not needed, and the first sensing electrode 31 on the front side of the film has a complete non-porous exposed shape so as to maintain consistent sensing performance.

In a preferred example, the viscosity of the paste used for printing to form the first conductive printing layer 20 is greater than the viscosity of the paste used for printing to form the second conductive printing layer 30. And controlling the transparent surface diffusion of the paste printed for the first time and the filling performance of the paste printed for the second time by using the viscosity difference of double-sided printing, and completing the double-sided conduction of the circuit film.

Specifically, referring to fig. 3, between the steps S1 and S2, after the first conductive printed layer 20 is baked, a back coating 60 is formed on the back surface of the insulating film 10 to protect the first conductive printed layer 20. After step S3, a front surface coating film 70 is formed on the front surface of the insulating film 10. More specifically, referring to fig. 1 and 2, the formation of the slot 13, the opening 14 and the outline of the insulating film 10 is performed after the formation of the front surface coating 70.

The embodiments of the present invention are merely preferred embodiments for easy understanding or implementing of the technical solutions of the present invention, and not intended to limit the scope of the present invention, and all equivalent changes in structure, shape and principle of the present invention should be covered by the claims of the present invention.

Claims (10)

1. A non-open hole double-sided conduction circuit film is characterized by comprising:

an insulating film (10) having a front surface and an opposite back surface, the insulating film (10) further having a first capillary stop hole (11) penetrating the front surface and the back surface;

the first conductive printing layer (20) is formed on the back surface of the insulating film (10), the first conductive printing layer (20) comprises a first overflow-preventing pad (21) which seals one end of the first capillary-preventing hole (11), and the first capillary-preventing hole (11) is used for preventing printing slurry of the first conductive printing layer (20) from overflowing to the front surface;

the second conductive printing layer (30) is formed on the front surface of the insulating film (10), the second conductive printing layer (30) comprises a first induction electrode (31) and a main circuit structure, the first induction electrode (31) is electrically connected to the first overflow-preventing pad (21) by the second conductive printing layer (30) in a mode that slurry is filled into the first capillary overflow-preventing hole (11), and the first overflow-preventing pad (21) is used for preventing printing slurry of the second conductive printing layer (30) from overflowing to the back surface.

2. The non-open-hole double-sided conducting circuit film as claimed in claim 1, wherein the first sensing electrode (31) and the first anti-overflow pad (21) are electrically connected via a plurality of first capillary blocking holes (11) located in the first sensing electrode (31), the first sensing electrode (31) is aligned with the first anti-overflow pad (21) and the coverage area of the first sensing electrode (31) is larger than that of the first anti-overflow pad (21).

3. The non-open hole double-sided conduction circuit film as claimed in claim 1, wherein the second conductive printed layer (30) comprises a short circuit (35) directly connected to the first sensing electrode (31), the first sensing electrode (31) is electrically connected to the first anti-overflow pad (21) via the short circuit (35) and one of the first capillary stop holes (11), and the first sensing electrode (31) is not aligned with the first anti-overflow pad (21).

4. The non-open-hole double-sided conduction circuit film as claimed in claim 1, wherein the second conductive printed layer (30) further comprises a second sensing electrode (32), the main circuit structure comprises a first connection circuit (33) not directly connected with the first sensing electrode (31) and a second connection circuit (34) directly connected with the second sensing electrode (32), the insulating film (10) further comprises a second capillary blocking hole (12) penetrating the front surface and the back surface, the first conductive printed layer (20) further comprises a second anti-overflow pad (22) and a trace (23) of a secondary circuit structure, the second anti-overflow pad (22) seals one end of the second capillary blocking hole (12), the trace (23) crosses over a part of the second sensing electrode (32) and connects the first anti-overflow pad (21) and the second anti-overflow pad (22), and the first connection circuit (33) is further filled with a paste The second capillary resistance holes (12) are electrically connected to the second resistance overflow pads (22), preferably, the routing wires (23) are connected in series with all the first resistance overflow pads (21), and the first sensing electrodes (31) are equipotential reference electrodes.

5. The non-open hole double-sided conductive circuit film according to claim 4, wherein a first connection terminal (41) electrically connected to the first connection line (33) and a second connection terminal (42) electrically connected to the second connection line (34) are arranged on the same surface wiring interface region of the front surface or the back surface, preferably, a test terminal (50) electrically connected in parallel by the second connection line (34) is arranged on the same surface test region of the front surface or the back surface, more preferably, the wiring interface region is located in the front surface, the test region is located in the back surface, and more preferably, a line connected to the surface test region is a fan-out extension toward the test terminal (50).

6. The non-exposure hole double-sided conduction circuit film of claim 5, wherein the insulation film (10) has a shape of a slot (13) on both sides of the flat cable interface region, so that the surface flat cable interface region is elongated.

7. The non-open hole double-sided conductive circuit film as claimed in claim 4, wherein the first sensing electrodes (31) have a circular pad shape, the second sensing electrodes (32) have a bad pad shape, and the second sensing electrodes (32) surround the first sensing electrodes (31) with the circle center of the first sensing electrodes (31) corresponding to each other as a circle center point.

8. The non-open hole double-sided conducting circuit film as claimed in claim 7, wherein the first sensing electrodes (31) and the second sensing electrodes (32) are arranged in pairs, a fixed gap is formed between each first sensing electrode (31) and the corresponding second sensing electrode (32), the first sensing electrodes (31) and the second sensing electrodes (32) arranged in pairs are arranged in the insulating film (10) in a staggered matrix manner, and preferably, the insulating film (10) forms openings (14) between the paired matrix adjacent points and the paired staggered points in the first sensing electrodes (31) and the second sensing electrodes (32) arranged in pairs.

9. The non-open-hole double-sided conduction circuit film according to any one of claims 1 to 8, further comprising a back-side coating film (60) formed on the back side and a front-side coating film (70) formed on the front side, wherein the back-side coating film (60) covers the first anti-overflow pad (21), the front-side coating film (70) covers the main wiring structure of the second conductive printing layer (30) and exposes the first sensing electrode (31) with an opening, the exposed surface of the first sensing electrode (31) is completely nonporous, the printing thickness of the first conductive printing layer (20) is preferably larger than that of the second conductive printing layer (30), the first capillary anti-blocking hole (11) has a unidirectional anti-blocking structure, and the front-side coating film (70) has an induction loop opening (71), for exposing the first and second sensing electrodes (31, 32) in a grouped configuration.

10. A method for manufacturing a non-open-hole double-sided conductive circuit film, for manufacturing a non-open-hole double-sided conductive circuit film according to any one of claims 1 to 9, the method comprising:

providing the insulating film (10), wherein the insulating film (10) is provided with the first capillary blocking hole (11) in advance;

back printing to form the first conductive printed layer (20);

front side printing to form the second conductive printed layer (30);

wherein the first sensing electrode (31) of the second conductive printed layer (30) has a shape of a complete non-porous exposed body;

preferably, the viscosity of a paste for printing to form the first conductive printing layer (20) is greater than the viscosity of a paste for printing to form the second conductive printing layer (30).

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